5) Set the flag on CPU 0 for one process and CPU 1 for the other
You can compare your computer's speed with other users by checking the
site http://www2.tripnet.se/~nlg/mersenne/benchmk.htm. If you are
much slower than comparable machines, download Microsoft's WinTop
kernel toy to find programs (such as AOL) that are stealing all of
prime95's CPU cycles. You can download the software free at
http://www.microsoft.com/windows/downloads/contents/powertoys/w95procwatcher
You can get a report of your PrimeNet server account status on the web
(http://entropia.com/primenet/status.shtml). Type your UserID and
password into the web form, and click "Get Account Report". You can
get your UserID and password from the Test/User Information
dialog box.
Information about running a local PrimeNet server is also available.
See http://entropia.com/primenet. If you have any questions about the
PrimeNet server, you can send e-mail to primenet@entropia.com.
The first time you run this program it will perform an hour long
self-test to make sure the Lucas-Lehmer code is running properly
on your system. There are 16 different self-tests, one for each
FFT size. You can run all 16 self-tests with Options/Self Test
menu choice. This is not required.
If you have overclocked your machine, I highly recommend running the
torture test for a couple of days. The longer you run the torture test
the greater the chance that you will uncover an error caused by
overheating.
Depending on the exponent being tested, the program may decide that it
would be wise to invest some time checking for small factors before
running a Lucas-Lehmer test. Furthermore, the program may start factoring
exponents before a previous Lucas-Lehmer test completes. This is normal!
The program will resume the Lucas-Lehmer test when the factoring
completes.
For manual users, once you've started testing a range there is no advantage
in downloading a new database. After your range completes, you can download
a new database before you start your next range.
You can configure this program to have different properties at different
times of the day and/or to not run during certain times of the day.
Unfortunately, you must manual edit the prime.ini file. Let's say you
want to install the program on a friend's machine and he runs a screen
saver at night. He also runs a disk defragmenter at midnight on weekdays.
This prime.ini file will run the program at a higher priority than his
screen saver at night and on weekends. It also sleeps for an hour when
his defragmenter starts running. Finally, at night fewer save files are
generated to allow his disk to stay powered down longer.
UserID=foo
Time=1-5/8:30-17:30
Priority=1
DiskWriteTime=30
Time=1-5/1:00-8:30,1-5/17:30-24:00,6-7/0:00-24:00
Priority=5
DiskWriteTime=240
The 1-5 refers to days of the week, with Monday=1 and Sunday=7. The
time portion refers to the hours of the day based on a 24-hour clock.
You do not need to specify days of the week (e.g. Time=1-7/0:00-8:00
is the same as Time=0:00-8:00). Unpredictable results will occur if
there are overlapping time intervals. Also note that any options that
appear in the Time= sections should not appear earlier in the prime.ini
file and you can no longer edit these options from theuser interface.
SETTING UP A PROXY SERVER
-------------------------
Create a file in the same local folder as Prime95.exe, called "primenet.ini".
Add these text lines, substituting the appropriate proxy server URL and port:
[PrimeNet Proxy]
ProxyHost=http://proxy.megacorp.com:8080
If the proxy is secured by a userid/password, add the following two text
lines, substituting the appropriate values:
ProxyUser=whatever_the_userid_is
ProxyPass=whatever_the_password_is
After the first time PrimeNet is contacted through a secure proxy, the proxy
password is encoded and a new parameter 'ProxyMask=1' set. To change the
password, simply change the ProxyPass= value, and either delete the ProxyMask
text line or set ProxyMask=0.
PROGRAM OUTPUT
--------------
On screen you will see:
Factored M400037 through 17517*2^32 (pass 3 of 16). Clocks: 24235224=0.121 sec.
This means prime95 is in the third pass of a 16 pass process to
find a small factor of 2^400037-1.
Iteration: 941400 / 1667747. Clocks: 21889762 = 0.109 sec.
This means prime95 just finished the 941400th iteration of a
Lucas-Lehmer primality test. The program must execute 1667747
iterations to complete the primality test. The average iteration
took 21889762 "clock cycles" or 0.109 seconds.
The results file and screen will include lines that look like:
M2645701 has a factor: 13412891051374103
This means to 2^2645701-1 is not prime. It is divisible
by 13412891051374103.
M2123027 no factor to 2^57, WS1: 14780E25
This means 2^2123027-1 has no factors less than 2^57. The Mersenne
number may or may not be prime. A Lucas-Lehmer test is needed
to determine the primality of the Mersenne number. WS1 is
the program version number. 14780E25 is a checksum to guard
against email transmission errors.
M1992031 is not prime. Res64: 6549369F4962ADE0. WT1: B253EF24,1414032,00000000
This means 2^1992031-1 is not prime - a Lucas-Lehmer test says so.
The last 64 bits of the last number in the Lucas-Lehmer sequence
is 6549369F4962ADE0. At some future date, another person will verify
this 64-bit result by rerunning the Lucas-Lehmer test. WT1 is the
program version number. B253EF24 is a checksum to guard against email
transmission errors. 1414032 can be ignored it is used as part
of the double-checking process. The final 00000000 value is a set
of 4 counters. These count the number of errors that occurred during
the Lucas-Lehmer test.
M11213 is prime! WS1: 579A579A
This means 2^11213-1 is a Mersenne prime! WS1 is the program
version number. 579A579A is a checksum to guard against email
transmission errors.
RUNNING PRIME95 ON SEVERAL COMPUTERS
------------------------------------
The easiest way to do this is to first set up prime95 on one computer.
Next copy all the files to the second computer. Delete the local.ini
file and worktodo.ini files. These files contain information that
is specific to the first computer. Start prime95 on the second
computer and optionally use Test/User Information to
give the second computer a unique computer ID. Repeat this process
for all the computers you wish to run prime95 on.
If you do not follow the instruction above, be sure you use
Test/User Information to give each computer the same
userid and password. Failure to do this will result in all
your work being "credited" to different user IDs.
TEST MENU
---------
The PrimeNet menu choice lets you configure the type of work you get
from the server. The "Use PrimeNet..." option can be turned on to
switch from the manual method to the automatic method.
The "Request whatever..." box should be left checked. However, if you
are running a slow computer and don't mind waiting several months for
a single Lucas-Lehmer test to complete OR you are running a faster
computer and would rather do factoring, then uncheck this box and
choose a different type of work to do. The "Days of work to get" should
be changed based on how often you connect to the Internet. As long as
you connect at least once in the given time period, prime95 will have
an uninterrupted stream of work. However, the program will not checkout
more than 20 exponents no matter what "Days of work to get" is set at.
The Manual Operation menu choice allows you to select a range of
exponents to work on. You may also use this menu choice to add
to your existing work (e.g. when you are running low on exponents
to test).
The User Information menu choice lets you change your name and email
address. Your name will be used in credits and "top producers"
web pages. Your email address will be used to send you warnings if
an exponent you have reserved is about to expire and to send you a
newsletter once every few months. Select the no email checkbox to
stop the server from sending expiration warnings. The userid you
use will appear in the status pages on the PrimeNet server. You can
also set the ComputerID field if you have several computers and want
to keep track of which computers produced which results.
The Vacation/Holiday menu choice lets prime95 update the expected completion
dates on the PrimeNet server. This will prevent one of your exponents
from being reassigned while you're gone. Also, if you are taking a
long vacation, prime95 will get extra exponents to test. For example,
if you are leaving immediately for a 6 week vacation, connect to the
Internet and choose 42 days. If you are leaving in two days for a 6
week vacation, then set choose 44 days. Primenet will send the new
completion dates whenever you connect to the Internet over the next 2 days.
The Status menu choice will tell you what exponents you are working on.
It will also estimate how long that will take and
your chances of finding a new Mersenne prime.
The Continue menu choice lets you resume prime95 after you have stopped it.
The Stop menu choice lets you stop the program. When you continue,
you will pick up right where you left off. This is the same as hitting
the ESC key.
ADVANCED MENU
-------------
You should not need to use the Advanced menu. This menu choice is
provided only for those who are curious to play with. To avoid confusion
for novice users, all the choices in the Advanced menu have been grayed.
Please read this section if you want to know what the Advanced menu choices
do. To turn on the Advanced menu, use the Advanced Password dialog box
and enter a value of 9876. Also note that many of the menu choices are
grayed while testing is in progress. Choose Test/Stop to activate
these menu choices.
The Test choice can be used to run a Lucas-Lehmer test on one Mersenne
number. Enter the Mersenne number's exponent - this must be a prime
number between 7 and 5259999.
The Time choice can be used to see how long each iteration of a Lucas-Lehmer
test will take on your computer and how long it will take to test a
given exponent. For example, if you want to know how long a Lucas-Lehmer
test will take to test the exponent 876543, choose Advanced/Time and
enter 876543 for 100 iterations. A Pentium will automatically time
and compute the results. 486 owners will need to time how long the operation
takes by hand, divide that time by 100 and multiply by 876543 to compute how
long a full Lucas-Lehmer test will take.
The ECM choice lets you factor small Mersenne exponents using the
Elliptic Curve Method of factoring. Select a few exponents and bounds
to factor from the http://www.mersenne.org/ecm.htm web page.
Note: You do not reserve exponents to work on, several people can
do ECM factoring on the same exponent. The program uses a random
number generator to select elliptic curves to test. You must email
results to me at woltman@magicnet.net - primenet does not support ECM
factoring. You can also edit the worktodo.ini file directly. For example:
ECM=751,3000000,0,100,0,0,0
The first value is the exponent. The second value is bound #1. The
third value is bound #2 - leave it as zero. The fourth value is the
number of curves to test. The fifth value is the number of curves completed.
The sixth value is the specific curve to test - it is only used in
debugging. The seventh value is 0 for 2^N-1 factoring, 1 for 2^N+1
factoring.
The Clear Primes choice can be used to remove one or more exponents from the
database. You might do this for two reasons:
1) Let's say you're testing range 1234000 to 1234999. If I send you some
mail saying that a factor has been found for M1234567, then you use
Clear Primes to remove 1234567 from your database so that you
won't have to run a Lucas-Lehmer test on it.
2) You downloaded a new database after checking all the exponents
between 1234000 and 1234300. You can use Clear Primes
to remove the exponents between 1234000 and 1234300.
Do not use the Factor menu choice. If you're running Lucas-Lehmer tests
on a range or just factoring a range - use Test/Manual Operation.
The program will know the optimal amount of factoring to perform. Having
said that, if you insist on using this menu choice, you can look for factors
less than 2^62 of any Mersenne numbers with an exponent less than 10,000,000.
Let's say you're writing a factoring program for a UNIX machine and want to
check its results. Use both this menu choice and your UNIX program to
search for small factors on a set of Mersenne numbers and compare the results.
Round off checking. This option will slow the program down by about 15%.
This option displays the smallest and largest "convolution error". The
convolution error must be less than 0.49 or the results will be incorrect.
There really is no good reason to turn this option on.
The Priority menu is used to adjust the priority prime95 runs at.
You should not need to change this. You might raise the priority
if you (or your coworker) just cannot live without your screen
saver (bad idea), or if you are running some ill-behaved program
that is using CPU cycles for no good reason.
The Manual Communication menu choice should only be used if the
automatic detection of an Internet connection is not working for you.
Using this option means you have to remember to communicate with the
server every week or two (by using this same menu choice).
The Quit GIMPS menu choice is used when you no longer want this computer
to work on the GIMPS project. You may rejoin at a later date.
If you are a PrimeNet user your unfinshed work will be returned to the
server. If you are a manual user, you need to send me email containing
your results.txt file and a note saying you are quitting.
OPTIONS MENU
------------
The CPU menu choice lets you tell the program what kind of CPU you
have. The program will normally figure this information out for you.
This information is used to give accurate time estimates in the
Test/Status menu choice. It is also used, to choose between integer
based factoring (Cyrix and 486) and floating point based factoring
(Pentium and Pentium Pro). No matter what you choose, the program
uses the same code to run the Lucas-Lehmer primality test. If you have
an AMD K5 or Cyrix M2 chip, choose Cyrix 6x86.
The Preferences menu choice lets you control how often a line is
written to the main window. Also how often a line is written to
the results file. It also lets you change how often
intermediate files (to guard against power failure an crashes)
are created. You can control how often the program checks to
see if you are connected to the Internet. The program polls
whenever it has new data to send to or work to get from the PrimeNet
server. If you are low on disk space, you can select one intermediate
file instead of two. However, if you crash in the middle of writing
the one intermediate file, you may have to restart an exponent from
scratch. You can also tell the program to be quiet, rather than
beeping like crazy, if a new Mersenne prime is found.
The Self Test choice lets you run a sixteen-hour self test. Passing the
self-test does not guarantee that you will not run into any hardware
problems later on, but it does give you some confidence that the program
is working properly.
The Torture Test choice will run a continuous self test. This is great
for testing machines for hardware problems.
The Tray Icon choice will cause prime95 to have a small icon on the taskbar
when it is minimized. You can activate the program by double-clicking on
the small icon. If you place the cursor over the small icon, a tooltip will
display the current status.
The No Icon choice is only enabled if the Advanced Menu is activated
with the password. Using this menu choice means there will be no
prime95 icon on the taskbar once you minimize the program (making it very
hard to reactivate!) If you turn this feature on and want to turn it
back off, edit prime.ini and change the line "HideIcon=1" to "HideIcon=0",